Ad hoc, wireless networks present
special challenges to the design of network protocols. Mobility
and multiple wireless hops on the path from a source node to
a destination lead to communications that are subject to fading,
high bit-error-rates and loss of connectivity. Protocols for
ad hoc, wireless networks are further complicated when the traffic
is multimedia data. Our objective in this project is to study
the behavior of network protocols in computer simulation. Previous
work has shown that communication exchanged between the MAC/data
link layers and the network layer of a node leads to better network
routing algorithms [Pursley, Russell, Staples, vol 17, no 5,
1999, JSAC]. We believe additional information exchanged between
the application layer and the lower layers will also lead to
overall improvements in network performance. For example, by
separating and identifying MPEG video streams into a base layer
and enhancement layers, intermediate nodes can immediately adapt
outgoing traffic patterns to changing bandwidth conditions prior
to notifying the source (which will ultimately adapts its rate).
In the other direction, the lower layers can assist in resource
reservation and provisioning by informing the higher layers of
existing conditions. More than just bandwidth availability, this
might include some measure of bandwidth fragility. Our simulation
environment includes a front-end hardware setup, similar to the
one used in [Krunz, Sass, Hughes 11(3) 1996, Int. J. of Comp.
Sys. Sci. & Eng.] for generating multimedia traffic and an
OPNET simulation of wireless communications network.

An undergraduate working on this
project will develop a variation of an existing simulation, gather
results and draw conclusions about the effect of their changes
on the system. In essence, the student is exposed to all aspects
of the research process. Because a large part of the infrastructure
is in place, the undergraduate will be able to gain a lot of
experience in a relatively short period of time.